Germanium

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

see section 13 of IUCLID for read across justification

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report):GeO2
- Molecular formula (if other than submission substance):GeO2
- Physical state:powder
- Composition of test material, percentage of components:>96%active
- Lot/batch No.:29506:856
- Stability under test conditions:stable under normal conditions
- Other:colour:white
-solubility: water: hexagonal structure:0.447%, tetrogonal structure non-soluble

Analytical monitoring:

yes

Details on sampling:

- Concentrations:0-6.24-12.5-25-50-100 mg GeO2/L
- Sampling method:samples were taken at the beginning and at the end of the test. 1 replica sample was taken of each test concentration. The samples were placed in PE bottles and 1% HNO3 was added to each sample.
- Sample storage conditions before analysis:stored at room temperature until shipment

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name:Daphnia magna
- Source:LISEC laboratory culture
- Age at study initiation (mean and range, SD):less than 24h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

according to OECD 202

Test temperature:

21.5-22.0 °C

pH:

7.89-8.34

Dissolved oxygen:

7.54-7.91

Nominal and measured concentrations:

Nominal concentrations: 0-6.24-12.5-24.9-99.8 mg GeO2/L
measured concentrations: 0-6.34-12.95-25.55-51.3-102.5 mg GeO2/L

Details on test conditions:

TEST SYSTEM
- Test vessel:50 mg borosilicate glass beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume:borosilicate glass beakers, 50 ml
- No. of organisms per vessel:5
- No. of vessels per concentration (replicates):4
- No. of vessels per control (replicates):4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:ISO 6341

OTHER TEST CONDITIONS
- Photoperiod:14h daily photoperiod

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study: yes
- Test concentrations:0-181 mg GeO2/L
- Results used to determine the conditions for the definitive study:upt to 18.1 mg GeO2/L: 0% immobilisation: 181 mg GeO2/L: 100% immobilisation

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

67.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: mean of 3 EC50s determined with Probit analysis (95%CI:53.1-93.1)

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12.95 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality of control: 0

Reported statistics and error estimates:

The EC50 values and their associated 95% confidence intervals (95%CI:53.1-93.1)were calculated using the TOXDAT Multi-method program (Stephan, 1985)

Validity criteria fulfilled:

yes

Conclusions:

Tests done according to standard protocol. Good quality and considered useful for setting the reference value for acute aquatic ecotoxicity

Executive summary:

Tests done according to standard protocol. Good quality and considered useful for setting the reference value for acute aquatic ecotoxicity. The 48 hrs LC50 was 67.5 mg GeO2/L, or 46.9 mg Ge/L.

Description of key information

Results on 2 species were available on the short-term toxicity to aquatic invertebrates. The LISEC study was conducted with GeO2 according to standard protocol. No studies on marine species were available.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

47 mg/L

Additional information

The 48h LC50 in the LISEC 2001 study was 67.5 mg GeO2/L. This corresponds to 47 mg Ge/L.

 

The study on Hyalella gave a unbound EC50 in tap water (> 3.1 mg/l). A low EC50 was observed in very soft water; this corresponds to a EC50 for Ge of 0.209 mg /L.